Warhead detonation indicator



Sept. 17, 1963 B. v. DINERMAN ETAL WARHEAD DEToNATIoN INDICATOR Filed April 24, 1962 llifow .ods 09| United States Patent O 3,104,353 WARHEAD DETONATION INDICATGR Bernhart V. Dinerman, Philadelphia, Pa., 'and Archie H.

Dove, Denver, Colo., assignors to the United States of America as represented by the Secretary of the Navy Filed Apr. 24, 1962, Ser. No. 190,523 7 Claims. 4(Cl. 34h- 213) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to detonation indicators and more particularly to a detection system for determining warhead detonation within the effective kill areav of a target.

A pilot engaged in an air-to-air missile attack with an enemy target frequently is unaware as to whether a launched missile detonates close enough to the target to damage the target. In many cases the pilot frequently cannot determine whether a launched missile detonates at all. This is particularly true in a long range attack and also under bad Weather conditions. At long ranges or under bad weather conditions visual observation of warhead detonation and damage assessment is frequently impossible. Even at short ranges and under ideal weather conditions it is not always possible for the pilot, who is absorbed in pressing the attack and viewing the system indicators, to know whether a warhead ldetonates and/or Whether the warhead fdetonates close enough to a selected target to inflect kill damage.

Inasmuch as the pilot cannot determine or assess damage to a tar-get, ground bases or airborne observation aircraft are relied upon to apprise the pilot of target dama-ge and the probable success or failure of his missile run. Since this method is so time consuming, the pilot has #little or no re-attack capability the 4first `group of launched missiles have proven ineffective. In addition the aboveJm-entioned method of target damage assessment is susceptible to electronic counter-measures orto saturation by large numbers of enemy aircraft. Therefore, it is desirable for an interceptor pilot to know immediately whether a launched missile or lgroup of missiles detonate well enough within the target area to damage the target. It is even more desir-able for the pilot to be made aware of the damage while the interceptor is still in the attack mode.

Thus, if the first missile or first 4group of missiles are ineffective in inflicting kill rdamage on the target the pilot is made aware of this and, therefore, may re-attack. On the other hand, if the intercept-or pilot is informed that the rst group of missiles launched most probably inflicted kill damage on the target, he knows that break away is in order. Such knowledge made available to the interceptor pilot broadens the field of interceptor effectiveness since the interceptor pilot may rie-attack the target if need be with no Waste of time or go on to a new attack with the remaining missiles.

'Ihe present invention co-ntemplates a system which detects missile detonation within kill range of the tanget Y, indication and continues his approach toward the target "ice tiring missiles until the target is killed. On the other hand, if luhe missile attack has been successful the pilot is so informed by a visual indication and is free to break way and seek a new target upon which to loose his remaining missiles. The presen-t invention contemplates a warhead detonation indicator which assesses damage to the target in which the outputs of two separate signal processing channels coincide when the attack has been successful. If the :outputs from the two separate signal processing channels [do not coincide, the pilot is informed that the attack has not succeeded and receives a re-attack signal.

One channel receives a voltage proportional to time-tomissile impact after launch of a missile and provides a gate-on signal to a coincidence circuit which straddles the predicted time lof missile impact. The other channel provides the coincidence circuit with signals indicative of infrared radiation caused by the ideto-nation of the missile. Therefore, detonations which occur within Ithe duration that the coincidence circuit is gated indicate to the pilot that detonation occurred at or near the predicted time of missile impact.

The Igate-on signal to the coincidence circuit which is controlled by the time to missile impact voltage generated in the Weapons system computer has a duration which is varied according to the effective kill range of the missile used and also according to the number of missiles iired in a burst. In other words, the duration of the gate-on signal is made suc-h that any missile that detcnates within the time duration :of the gate-on signal is effective to destroy the selected target.

A11-object of the present invention is to provide a system which detects detonation of a missile Within kill range of a target.

Another object of the present invention is to provide a system which visually indicates to an interceptor pilot Whether or not a missile :or a group of missiles launched from the interceptor detonate within a specified area in which there is a target.

A further :object of the present invention is to provide a system for use in an interceptor which immediately signals the interceptor pilot while still in the attack mode to re-attack or break away based -upon information concerning the edectiveness of Va previous attack.

Still another object of the present invention is to provide a detonation detection and indicator system which enables an interceptor pilot to make an accurate assessment of probable kill of a target while still in an attack mode and in time to launch another or more missiles to a target if the target has not been destroyed.

The FIGURE illustrates partly in block diagram form and partly in schematic form the preferred embodiment of the system `of the present invention.

Referring now to the ligure there is shown a lire control computer 11 having an output terminal connected to the base of transistor 12. 'llhe emitter of transistor 12 is connected to ground through a resistance 13 and the collector is connected to a 28 volt D.C. voltage source through relay coil 14. Diode 16 is shunted across relay coil 14 to provide a leakage pass through the relay coil 14 when it 'is deenergized. The 28 volt D C. voltage source is connected to the base :of transistor 12 through resistor 17. 'Ilhe base of `transistor 12 is connected to ground through resistor 1S which, together with resistor 17, forms a divider bias type network.

The normal state of relay 14 is to be energized. Fire control computer 11 provides Ia voltage on its output terminal to the base of transistor 12 suiciently large enough to overcome the bias of transistor 12 to maintain it conducting. When a missile is released this voltage starts decreasing linearly :as the missile approaches the point of impact. This computed voltage is at a maximum value when the missile is launched and linearly decreases to zero when the missile reaches the predicted point of impact. When this voltage reaches a predetermined value, e.g., 0.5 volts indicative of the missile somewhat before the missile reaches the point of predicted impact, transistor 12 is cut off preventing current lflow through the coil 14a.

While relay l141 is energized, the yarm 146 of relay 14 is on the dead contact as shown. When the voltage from computer 11 reaches 0.5 volts, transistor 12 is cut off causing the arm 14h of relay 14 to make the upper contact.

Trigger amplifier 21 has a plate 22 connected to a 250 D.C. positive voltage source through resistor 26. Cathode 25 of trigger amplifier `21 is connected to ground. The grid 24 of 4trigger amplifier 21 is connected to the upper contact of relay arm 14h through capacitor 27. The arm 1412 of relay 14 is connected to the 250 D.C. positive voltage source. `Resistors 2S and 29 form a biasing network for grid 24 to maintain trigger amplifier 21 below cutoff as long as switch arm Mb of relay 14 is in the position shown.

Tubes 31 and 32 together form a multivibrator. The plate 33 of tube 31 is directly connected to the plate 22 of trigger amplifier 21. The plate of tube 32 is connected to the 150 volt negative voltage source through resistor 44. The cathodes 36 and 39 of tubes 311 and 32, respectively, are connected to ground through resistor 41. The grid 38 of tube 32 is connected to the plate of trigger amplifier 21 through capacitor 43. The grid 34 of tube 31 is connected to the wiper arm of a resistor 42 which is connected between ground and the 250 volt positive voltage source. A resistor 46 is connected between the 250 volt positive voltage source and the grid 38 of tube 32. Another resistor 47 is connected to the 150 volt negative voltage source through resistor 44 and to the 250 volt positive voltage source. The plate of tube 32 is connected directly to the gridAS of coincidence tube 51.

As previously mentioned the 0.5 volt D.C. level at which transistor 12 is made nonconductive is selected to assure that the gate-on pulse starts before the predicted detonation time. When the arm Mb of relay 14 makes the upper contact, the 250 volt positive voltage source supplies a positive pulse through capacitor -27 to the grid 24 of trigger amplitier 21. This pulse overcomes the normal cutoff bias on trigger ampliiier 21 and causes the tube to conduct. When trigger amplifier 21 is made conductive, current iiow in resistor 26 causes the voltage of the plate 22 of trigger amplifier 21 to drop. This furnishes a negative trigger to grid 38 of tube 32 through capacitor 43. The values of resistors 42 and 46 along with the value of capacitor i3 determine the duration of the positive pulse output of the multivibrator formed by tubes 31 and 32. The actual pulse width of the positive pulse which appears on the output of plate 37 of tube 32 may be controlled by potentiometer 42. The variable gate width multivibrator output pulse from tube 32 establishes the time to missile impact gate and being supplied to the grid 4S of coincidence tube 51, coincidence tube is put into a partially conducting state preparatory to accepting signals representative of the detonation of the missiles.

The second input to coincidence tube 51 is supplied by a conventional infrared radiation detector 20 which detects infrared radiation caused by detonation of a missile and converts such into a voltage. This voltage is supplied to trigger amplifier 30 to trigger multivibrator 40 which provides a pulse output for every 'detonation that infrared radiation detector 2li detects. Multivibrator 4t) and differentiator network 50 together form a pulse shaping network. The output of diiferentiator network t) is connected directly to the grid 49 of coincidence tube 51. Missile detonation signals at grid `49 of coincidence tube S1 that occur during the time to missile impact gates at grid 48 of tube 51 produce output pulses at the plate 53 which are supplied to elements 6G* and 76 which together form a ring counter more fully explained herein 7 below.

The ring counter of this invention comprises a binary element enclosed by dotted line 6i? which is used `as the reset and re-attack stage. The other stage 70 consists of four multivibrators of which only one is shown since the others are exact duplicates. Multivibrator l60 responds only to the leading and trailing edges of the time to missile impact gate from coincidence tube 51, while the multivibrator stage 70 counts one to four lighting a lamp representing the number of detonation signals recevied during time to missile impact gate.

The pulses from the plate of coincidence tube 51 are shaped and clamped by the circuit consisting of diodes 54 and S6, capacitors 53 and 57, and resistor 59. The values of these elements are selected to assure acceptance of the desired pulse and rejection of noise pulses from the output of coincidence tube 51.

Although the counter stage 70 consists of four multivibrators and is capable of counting up to four detonations which occur during the gate-on pulse to the coincidence tube 51, only the situation where one missile is fired will be discussed. This is to provide a simplified explanation of the ring counter operation.

Re-attack stage 6@ comprises a multivibrator having a normally conducting tube 59 and a normally nonconducting tube 61. The counting stage 70 comprises a multivibrator having a normally nonconducting tube 62 and a normally conducting tube 63. The cathode of tube 59 is directly connected to the cathode of tube 62 while thc cathode of tube 61 is directly connected to the cathode of tube 63. The plate 53 of coincidence tube 51 is connected to the grids of tubes 61 and 63 through appropriate biasing circuits.

When a missile detonation occurs within the time duration of the gate-on pulse, a negative pulse having an `amplitude greater than l60 volts is applied to the cathode of tube 62 causing tube 62 to become conductive and tube 63 to become nonconductive. Conduction of tube 62 causes neon tube 66 to be energized. When neon tube 66 is lighted, it indicates that a missile has detonated within kill range of a target. The situation in which several missiles up to four are launched against a target yand in which additional stages similar to 76 are required will be discussed more fully hereinbelow.

After a missile is launched, there are two situations which may occur. The tirst situation is detonation and detection of detonation of the missile during the gate-on period of coincidence circuit S1 in which case tube 62 is made conducting and tube 63 will be made nonconducting. For this situation when the gate-on pulse terminates, a positive pulse from the trailing edge of the negative gate is accepted at the grid of tube 63 causing it to conduct thereby deenergizing neon lamp 66. This resets the system to normal pre-detonation operation.

rI'he second situation which may occur is no detected detonation during the gate-on period. For this case the steady state of stage 70 is unchanged. Although the positive going pulse on conductor 67 is ineffective to change the normally conducting state of tube 63, it causes tube 61 to become conductive. When tube 61 becomes conductive, neon tube 64 is energized indicating that no .missile has detonated close enough to the target to destroy the target and that re-attack is in order. The re-attack light 64 is extinguished when a negative pulse produced fby lformation of a new gate at coincidence tube 51 is applied to the grid of tube 61 which stops conduction therein.

For the case where up to four missiles are launched against a target and where it is desired to know hcw many of those missiles detonated within the kill range of the target, additional stages may be used identical to the stage 70 which count up to four in response to the number of detonation signals passing through coincidence circuit during the gate-on period. Each of the stages are alike in structure and each has a neon lampsimilar to the neon lamp 66. Thus, if two missile detonations occur during the ygate-on period the first detonation signal will cause neon lamp 66 to be energized when tube 67. is made conductive and tube 63 non-conductive. At the same time, a positive pulse from 63 will flip the second stage preparatory to receipt of the next detected detonation signal. This pulse will be applied to the second stage via conductor 69.

In an operation similar to that discussed for stage 70, the second stage, upon receipt of the next detected detonation signal at the common A cathodess, will have its conductive B section state changed to light a second neon lamp indicative of the second detonation occurring during the same gate-on period. Similarly, for three or four detonations occurring during the gate-'on period, the third or fourth neon light will be energized. Conductor 67 is extended to connect to the respective B section grids in each respective stage, thereby permitting the positive going pulse caused by the trailing edge of the gateon pulse to be applied to each of the respective grids and to be effective in furnishing reset or reattack signals, depending upon the success of the missile attack. The manner in which the neon tube 64 is energized to indicate or give a visual reattack signal is similar to that already discussed. In the event detonation signals are detected, the K-Z relay prevents the reattack light 64 from being energized due to the opening of the relay contacts in series with tufbe 64. The K-Z relay is operated by a detonation pulse to open the circuit to neon tube 64. Thus, the trailing edge of gate-on pulse still ips stage `60 but neon light is prevented from indicating reattack. Stage 60 is reset by the leading edge of the next gate-on pulse. The circuit for relay K-Z is in practice similar to that of relay 14.

The detonation pulses are supplied to the A cathodes of the next stages via conductor 71. 4It is noted that these stages are unaffected by the detonation pulses unless previously conditioned -by the change in plate voltage at the B plates which accompanies the dipping by a detonation pulse of that particular stage.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the linvention may be practiced otherwise than as specifically described.

What is claimed is:

l. A warhead detonation indicator system for use in an interceptor aircraft for Idetecting Idetonation of missile warheads Within a selected target area, comprising in combination:

lgate generator means providing a gate pulse a predetermined time after the tiring of a missile and having a predetermined interval of duration,

explosion detector means generating a pulse in response to missile warhead detonation,

gate circuit means connected to said lgate generator means and said explosion detector means providing an output pulse for each missile warhead detonation occurring during said interval, counter means connected `to said coincidence circuit responsive to each of said output pulses for indicating the number of detonations occurring during said interval,

indicator means connected to said gate generator means providing an indication when no detonations occur during said interval. 2. A warhead detonation indicator system for use in an interceptor aircraft for detecting detonations of missile warheads within a selected target area, comprising in combination:

ire control computer means providing a linearly decaying voltage as an output when a missile is tired,

multivibrator means connected to said lire control means providing an output gate pulse of predetermined lduration when said linearly decaying voltage reaches a predetermined value,

radiation detector means responsive to warhead detonations providing an electrical pulse in response to eac-h detonation,

coincidence circuit means connected to said multivibrator means and said radiation detector means pro- 5 viding an output pulse for `cach detonation pulse occurring during the interval of said gate pulse,

display means connectedto said coincidence circuit indicating the number of detonations occurring dur- 10 ing said interval and providing an indication when no detonations occur during said interval.

li. A system accor-ding to claim 2 wherein said display means comprises:

iirst multivbrator means havin-g a neon tube connected across the normally nonconducting side thereof, means connecting said coincidence circuit to said first multivibrator means for changing the conductive state of said rst multivibrator means and lighting said neon tube when no detonations occur during said interval,

counter means connected to said coincidence circuit for counting and indicating the number of warhead detonations occurring within said interval, lwhereby the interceptor pilot is informed whether or not warhead detonation has occurred within the selected target area.

Mt. A system according to claim 3 wherein said counter means comprises:

second multivibrator means having neon tube means connected across the normally nonconducting side thereof,

means connecting said coincidence circuit .to said second multivibrator means for changing the conductive state of said second multivibrator means according to the number of said detonation pulses,

whereby said neon tube means indicates the number of ydetonations occurring during said interval.

5. A warhead idetonation indicator system for use in an interceptor aircraft for idetecting detonations of missile warheads within a selected target area, comprising in combination:

fire control computer means providing a linearly decaying voltage as an output when a missile is red from the aircraft,

multivibrator means connected to said re control computer means providing an output gate pulse when said linearly decaying voltage reaches a predetermined value, said multivibrator means including resistor means for varying the duration of said output gate pulse,

radiation detector means responsive to missile warhead detonations providing an electrical pulse in response to each detonation, coincidence circuit means connected to said multivibrator means gated by said output gate pulse,

means connecting said radiation detector means to said coincidence circuit for each 1detonation pulse occurrring during the interval of said 4gate pulse,

display means connected to said coincidence circuit providing an indication of the number of detonations occurring during said interval and an indication when no detonations occur dur-ing said interval. l6. A system according to claim 5 wherein said display means comprises:

first multivibrator means having a neon tube connected across the normally nonconducting side thereof,

means connecting said coincidence circuit to said first multivibrator means for changing the conductive state of said first multivibrator means and lighting said neon tube when no detonations occur during said interval,

counter means connected to said coincidence circuit for counting and indicating the number of warhead detonations occurring' within said interval, whereby the interceptor pilot is informed Whether or not warhead detonation has occurred within the selected target area.

7. A system according to claim 6 wherein said counter means comprises:

second multivibrator means having neon tube means connected across the normally nonconducting side thereof,

means connecting said coincidence circuit to said second multivibrator means for changing the conductive state detonations occurring during said interval.

References Cited in the le of this patent UNITED STATES PATENTS Snelling Oct. 28, 1947 MacDonald Jan. 23, 1962 

1. A WARHEAD DETONATION INDICATOR SYSTEM FOR USE IN AN INTERCEPTOR AIRCRAFT FOR DETECTING DETONATION OF MISSILE WARHEADS WITHIN A SELECTED TARGET AREA, COMPRISING IN COMBINATION: GATE GENERATOR MEANS PROVIDING A GATE PULSE A PREDETERMINED TIME AFTER THE FIRING OF A MISSILE AND HAVING A PREDETERMINED INTERVAL OF DURATION, EXPLOSION DETECTOR MEANS GENERATING A PULSE IN RESPONSE TO MISSILE WARHEAD DETONATION, GATE CIRCUIT MEANS CONNECTED TO SAID GATE GENERATOR MEANS AND SAID EXPLOSION DETECTOR MEANS PROVIDING AN OUTPUT PULSE FOR EACH MISSILE WARHEAD DETONATION OCCURRING DURING SAID INTERVAL, COUNTER MEANS CONNECTED TO SAID COINCIDENCE CIRCUIT RESPONSIVE TO EACH OF SAID OUTPUT PULSES FOR INDICATING THE NUMBER OF DETONATIONS OCCURRING DURING SAID INTERVAL, INDICATOR MEANS CONNECTED TO SAID GATE GENERATOR MEANS PROVIDING AN INDICATION WHEN NO DETONATIONS OCCUR DURING SAID INTERVAL. 